中文摘要：

利用立方硅氧烷（odaaps）作为保护剂合成了金纳米颗粒，利用紫外-可见（UV-vis）吸收光谱、透射电镜（TEM）对纳米颗粒进行了表征。通过改变纳米溶胶的pH值，从而改变立方硅氧烷上羧基的存在形式，控制纳米颗粒表面的电荷，实现金纳米颗粒的可逆聚集与分散；当将其pH值降低至2．5时。颗粒能够完全沉淀，加碱调节其pH与原始值（pH=9）一致时，聚集的颗粒会自动重新分散形成溶胶，其具有与起始一致的高分散性。

英文摘要：

Au nanoparticles were synthesized under the protection of odaaps. UV-vis spectra, transmission electronic microscopy were used to characterize the nanoparticles. The charge distribution on Au nanoparticles＇ surface can be changed with the different pH values of Au colloids, by which the reversible process of aggregation and redispersion can be achieved. When the pH value of Au colloids was adjusted to 2. 5, the nanoparticles began to precipitate. When adjusting pH to 9. 0, the precipitated particles can be redispersed automatically to form Au coLLoids with high dispersion as originally.